1. Field of the Invention
The present invention relates generally to a bracket for locking a sensor into a predetermined position. More particularly, the present invention relates to a bracket for temporarily locking an automotive height sensor into a predetermined position during the manufacture of the vehicle.
2. Disclosure Information
Automotive height sensors determine the distance between the sprung and unsprung vehicle masses and send an electronic signal to a suspension control module which determines whether to increase or decrease the vehicle ride height. For example, in an air suspension system, the module maintains proper vehicle ride height (vehicle "trim") by regulating the air pressure in the air springs. It is essential that the height sensors are calibrated when the vehicle is manufactured to assure proper vehicle height measurement.
To assure proper operation of the suspension system, the height sensor signal must correspond to the vehicle ride height. This can be accomplished during manufacture of the vehicle by holding the vehicle suspension at the trim height while the sensor attachment points are adjusted to the trim dimension. One method for assuring that the sensor attachment points are at the correct trim position is to lock the height sensor in a predetermined position prior to its installation in the vehicle. After the height sensor is attached to the vehicle at the sensor attachments, the attachments can be tightened into position to ensure that the vehicle is in trim when the sensor is at its trim position.
Various methods of locking the height sensor into a predetermined position have been proposed. For example, U.S. Pat. No. 4,555,120 proposes to ultrasonically spot weld the height sensor shaft to the sensor housing to temporarily lock the sensor components in a predetermined position prior to installation into the vehicle. Upon installation, the weld is broken upon a compression of the shaft relative to the sensor housing.
U.S. Pat. No. 4,930,340 proposes the use of a retaining bracket which temporarily locks the sensor shaft in a predetermined relationship to the sensor housing. The bracket includes a pair of apertures which fit over a respective pair of bosses on the sensor housing and the sensor shaft to hold the sensor components in a predetermined position. After installation of the height sensor into the vehicle, the bracket of the '340 patent is stripped from the sensor upon an extension of the sensor shaft from the housing and a successive retraction of the shaft into the housing. As fully described in the '340 patent, the bracket will not automatically strip from the bracket unless both the extension and retraction of the sensor is completed. However, it is not always possible during the manufacturing of the vehicle to subject the height sensor to an extension followed by a successive retraction. In such cases, the retaining bracket of the '340 patent will not automatically strip from the sensor, making it necessary for an operator to physically remove the bracket from the sensor.
Therefore, there is a need for a bracket which temporarily locks a sensor into a predetermined position which can be automatically stripped away from the bracket upon either an extension or a retraction of the sensor shaft relative to the sensor housing. It is an object of the present invention to provide such a bracket.